1. Field of the Invention
The present invention relates to an electric motor and an electric power steering apparatus including the same, and more particularly to an electric motor and an electric power steering apparatus including the same, by which problems such as a malfunction of an electric motor, damage to a component of the electric motor, and lowering of an output of the electric motor can be solved by preventing penetration of foreign substances into the electric motor, so that a steering stability of a vehicle can be improved.
2. Description of the Prior Art
FIG. 1 is a schematic diagram of a rack-driven power steering apparatus according to the related art.
As illustrated in FIG. 1, the rack-driven power steering apparatus, according to the related art, includes a driving unit 120 controlled by an electronic control unit (ECU) configured to determine a steering degree of a steering wheel 113 through a torque sensor 111 mounted to an upper end of a steering column 110, for generating power, a rack bar 130 for moving tie rods 133 connected to wheels 131 according to the steering degree of the steering wheel 113, and a driven unit 140 for receiving a rotational force of the driving unit 120, and converting the received rotational force into an axial movement force to transmit the axial movement force to the rack bar 130.
Here, the driving unit 120 includes an electric motor 121 controlled by the electronic control unit (ECU), a driving pulley 125 coupled to a shaft 123 of the electric motor 121, and a driving belt 127 wound on the driving pulley 125, and the driven unit 140 include a ball nut 141 for supporting the rack bar 130 inside a rack housing surrounding the rack bar 130, and a driven pulley 143 assembled on an outer peripheral surface of the ball nut 141.
The driven pulley 143 coupled to the driving pulley 125 connected to the shaft 123 of the electric motor 121 and the driven pulley 143 coupled to the ball nut 141 are disposed in parallel, and the driving belt 127 is mounted on the driving pulley 125 and the driven pulley 143 to transmit the rotational force of the electric motor 121 to the rack bar 130. The rack bar 130 is moved leftwards and rightwards by an operation of the ball nut 141 to generate an assistant force.
However, in the rack-driven power steering apparatus according to the related art, foreign substances are introduced between the housing and the shaft of the electric motor which causes electric motor malfunction, damage to a component of the electric motor, and lowers the output of the electric motor, and accordingly, the steering stability of a vehicle cannot be secured.